Folding staircase



NOV. 5, 1968 A R, CRlPE ET AL 3,408,959

FOLDING STAIRCASE Filed July 24, 1967 2 sheets-sheet 1 NOV. 5, 1968 A, R GRIPE ET AL 3,408,959

FOLDING STAIRCASE Filed July 24, 1967 2 Sheets-Sheet United States Patent-O 3,408,959 FOLDING STAIRCASE Alan R. Cripe, Richmond, Va., and Walter C. Caylor,

Wethersfield, Conn., assignors to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Filed July 24, 1967, Ser. No. 655,357 6 Claims. (Cl. 105-447) ABSTRACT OF THE DISCLOSURE A folding staircase for a passenger vehicle that converts from a platform in the vestibule of the vehicle to a pair of steps extending outwardly from the door of the vestibule and down to a station platform. The convertible staircase pivots 180 around the vehicles doorsill by means of an arm and link mechanism to fold from the exterior stair position into the interior platform position.

Background of the invention Field of invention.-This invention relates to a staircase for entering and leaving a passenger vehicle and more particularly to a convertible staircase that folds from a staircase position external of the vehicle into a platform in the vestibule of the vehicle.

Description of the prior art.-In the construction of staircases for railway vehicles, it has been the general practice to provide a pair of rigid steps -that are covered by a separate platform located thereabove. The outer portion of the staircase is open to the element-s and, therefore, subject to the formation of snow, ice and sleet on the treads. The stairs project downwardly from the car body increasing the air resistance under the car frame, and are usually covered by a trap door that must be raised manually before a passenger can enter or leave the car by way of the staircase.

One of the railway passenger-vehicle staircases of the prior art comprises a series of individually hinged steps that can be successively folded so that one or more of them can be extended for use. This particular type of construction does not permit the staircase to be converted into a platform inside the vestibule when the staircase is not in use. A construction of this type is shown in United States Patent No. 976,195.

Another of the railroad passenger cars of the prior art utilizes a secondary staircase that slides down over a fixed staircase, thereby covering any ice or snow thereon (United States Patent No. 1,397,294). When the secondary stairs are raised, they form a platform that becomes an integral part of the vestibule floor inside the car.

Another staircase device, as shown in the patent to A. F. Paul, United States Patent No. 1,802,926, employs a trap door in the floor of the car vestibule that can be lowered into stair-forming position to enable passengers to pass in and out of the car from low-level platforms. The stair treads move at the same time, but at different rates of speed so that they are simultaneously brought into the trap door forming position or into the stair-forming position.

In all of the above mentioned staircase devices, the mechanism for raising, lowering or folding the stairs and converting them from platform to stairway position is unduly complicated and comprises a series of chain or pulley drives with associated linkages. All of these staircases are contained inside the passenger vehicle when converted from a platform to a stair-forming position, and none of them can be extended outwardly from the side of the train to rest upon a station platform. None of the staircases of the prior art suggestthe formation of 3,408,959 Patented Nov. 5, 1968 ICC an interior platform step that will aid la passenger in reaching a station platform at a higher level than the iloor of the passenger vehicle vestibule.

Summary of invention An object of the invention is to provide a passengervehicle staircase that extends outwardly from the vehicle vestibule at passenger stations having low level platforms and which converts into a platform inside the car in the vestibule for use at stations having high-level platforms.

In accordance with one aspect of the present invention, a staircase is provided which quickly converts from a platform step inside the vehicle and above the vestibule floor, into a set of stairs extending from the vestibule floor outwardly from the vehicle to rest on a low level station platform.

When in the platform-step position, the convertible staircase of this invention forms a step above the vestibule oor of the vehicle so that passengers can ascend from the floor by way of the platform step, up and onto a high level station platform.

At stations having a passenger platform lower than the vehicles vestibule iloor, the convertible staircase is extended from the side of the car to permit exit to the low level passenger platform. Passengers descend directly from the vestibule floor, down the stair treads to the station passenger platform. The botom tread of the stair is hingedly attached to its upper tread, and, therefore, the bottom tread is free floating and self adjusting, enabling it to rest rmly on low level passenger platforms that vary in height or with very low platforms to assume a position thereabove but normal height beneath the next higher step.

The invention accordingly provides a passenger vehicle staircase operated by a simple mechanism and one that can be utilized with great ease at passenger platforms above and below the level of the vehicle vestibule floor.

The foregoing and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of a preferred embodiment thereof as ilustrated in the accompanying drawings.

Brief description of the drawings FIGURE 1 is a perspective view of a preferred embodiment of the invention showing the staircase in the extended position.

FIGURE 2 is a side view of the preferred embodiment of the invention and shows the convertible staircase Iin the stair-forming position.

FIGURE 3 is a side view of the invention showing the staircase converted into a platform step above the vestibule floor.

Description of the preferred embodiment Referring generally to the preferred embodiment of FIGURES 1, 2 and 3, a staircase 10, comprises a lower tread 12, an upper tread 14, a lower riser 16, and an upper riser 18. The top edge of riser 18 is riveted t0 a hinged member 20 (FIGURES 2 and 3) and is pivotally connected to the frame 21 of the vehicle door at points 22 (FIGURE 1) in the side 24 of a passenger vehicle. By pivoting around hinge 20, the staircase 10 can be converted from the stair-forming position, 'shown in FIG- URES 1 and 2, to the platform-step position illustrated in FIGURE 3. Two upper side frames 26 serve as supports for upper tread 14 and upper riser 18. Each of these side frames 26 is rmly attached to tread 14 and riser 18 to form a single assembly that is riveted or welded to hinge 20. The lower riser 16 is hingedly connected to the bottom of the upper riser 18 at point 28 (see FIGURE 2).

A lower side frame 30 is welded to each end of lower tread 12, as shown in FIGURES 1 and 2. A supporting stop member'32 is welded to each of the side frames 30, as well as to the lower tread 12. In this way, side frames 30, support stops 32, and lower tread 12 form a single structure.

The upper side frames 26 and the lower side frames 30 are operatively connected by connecting arms 34 using pins 36. and 38.A Additionally, the rear portion of tread 12 is pivotally connected to the bottom portion of the riser 16 at point 40, more clearly seen in FIGURE 2. Because of the pivoting action just described about points 28, 36, 38 and 40, tread 12 is free to swing up and down in the horizontal plane. This type of construction gives thelower tread 12 considerable freedom in movement and also maintains the lower tread in parallel relationship to the upper tread 14 at all times. Therefore, staircase 10 is self adjusting to varying platform heights at different passenger stations.

In FIGURES 2 and 3, the mechanism for converting the staircase 10 from the step-forming position to the platform step position is more clearly shown. The staircase 10 pivots about points 22 (FIGURE 1) by the action of an arm 42 and a link 44 driven by a drive motor 46. The arm 42 is fixedly attached to a rotatable gear 52 that is operatively connected to a drive motor 46 by a conventional chain or belt 54. When the staircase is in the stair-forming position shown in FIGURE 2, arm 42 comes to rest against a stop 56, which is fixedly attached to a brace 58 inside the framework of the passenger vehicle. The vehicle has a vestibule floor 60 that extends to the edge of the car door, as illustrated in FIGURE 3. When the staircase 10 is converted into the platform step position, shown in FIGURE 3, support stops 32 rest against the top of the oor 60 to rmly support the treads 12, 14 and riser 16. The horizontal platform step in FIGURE 3 comprises riser 16 and tread 12.

The frame member 62 forms an extension of the upper stair tread 16 and is attached thereto to form a continuation of the step platform between the outer surface 24 of the car and the forward end 64 of the platform step (see FIGURE 3). Outside member 66 is attached to the end of frame member 62 and riveted onto hinge 20 thereby forming the outside surface of the vehicle when the staircase is converted from the step position to the platform position.

The following two situations wherein a passenger can utilize the convertible staircase to enter and leave the passenger vehicle, emphasize the advantages of this invention.

In railway stations where the passenger platform is at a higher level than the floor of the vehicle, a passenger entering or leaving the vehicle steps upon the platform step, illustrated in FIGURE 3, thereby eliminating the discomfort and danger of a large step up or down.

At most stations the passenger platform is at a lower level than the oor of the vehicle. As the passenger vehicle comes to a stop at these stations, the conductor opens the door of the car and energizes motor 46 which, in turn, drives chain 54 and gear 52, thereby rotating arm 42 and connecting link 44 (FIGURE 3) counterclockwise. The arm 42 and the link 44 extend outwardly through the open doorway carrying the convertible staircase 10 along therewith and down to the station platform level. As the staircase 10 passes through the doorway, it unfolds and the bottom tread 12 folds down along with the bottom riser 16. The unfolding action stops when the upper ends 35 of connecting arms 34 come to rest against the bottom side of upper tread 14, thereby preventing the lower tread 12 from dropping further. As mentioned hereinbefore, the free-floating action of tread 12 about pivot points 38 and 40, enables the staircase to adjust itself vertically to compensate for variations in station platform height.

Adjustable stops 56 are provided to regulate and stop the extension of arms 42 so that when the arms and staircase 10 are extended, as shown in FIGURE 2, rotation of the arms 42 and the staircase 10 will stop at a preselected position.

With the staircase 10 in this stair position, shown in FIGURE 2, passengers enter and leave thelcar by means of treads 12 and 14, 'stepping to or fromthe vestibule floor 60.

Before the vehicle leaves the station, vthe conductor energizes drive motor 46 and the staircase 10 begins its clockwise rotation about hinge 20, folding into a platform step with the support stops 32 coming to rest on the vestibule lloor 60:

The microlimit switch 68, illustrated in FIGURE 3, is utilized to deenergize the motor 46, automatically, when the staircase 10 has been converted into the platformstep condition. As arms 42 pivot clockwise, the forward edge of one of the arms comes into contact with the switch 68 at point 70, thereby deactuating the motor 46. Similarly, microlimit switch 72 deenergizes motor 46, automatically, when staircase 10 has been converted into the stair position.

Although the invention has been shown and described with respect to a preferred embodiment thereof, it should be understood by those skilled in the art that the foregoing and other changes and omissions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention, which is to be limited and dened only as set forth in the following claims.

We claim:

1. A staircase for a railway vehicle that converts from a platform position in the vestibule inside the vehicle doorsill to stair-forming position leading to a station platform which comprises:

a pair of stair treads separated by a lower riser and pivotally connected thereto, said treads comprising a lower tread and upper tread; U

an upper riser pivotally connected to said upper tread and pivotally connected to the frame of the vehicle doorsill;

a lirst side frame tixedly attached to said upper tread and said upper riser at each end thereof;

a connecting arm member pivotally connecting said lower and said upper treads at each end thereof and parallel to said lower riser and spaced therefrom, said connecting` arm member and said lower riser being free to pivot to orient said lower tread from a position coplanar with said upper tread to a'position parallel to but beneath said upper tread and carrying said lower tread attached thereto;

an arm and link mechanism pivotally connected to each of said first side frames;

and power means for actuating said arm and link mechanisms, so that when said power means is energized said arm and link mechanisms are actuated, causing the staircase to pivot about the vehicle doorsill and into the vehicle vestibule to form a platform.

2. A staircase for a railway vehicle that converts from a platform-step position above the vestibule oor inside the vehicle doorsill to stair-forming position leading to a station platform which comprises:

a pair of stair treads separated by a lower riser and pivotally connected thereto, said treads comprising a lower tread and upper tread;

an upper riser pivotally connected to said upper tread and pivotally connected to the frame of the vehicle doorsill; Y

a first side frame fixedly attached to said upper tread and said upper riser at each end thereof;

a connecting arm member pivotally connecting said lower and said upper treads at each end thereof and parallel to said lower riser and spaced therefrom, said connecting arm member and said lower riser being free to pivot under said upper tread from a position coplanar therewith to a position parallel to but beneath in open position and carrying said lower tread attached thereto;

an arm and link mechanism pivotally connected to each of said first side frames;

and power means for actuating said arm and link mechanisms, so that when said power means is energized said arm and link mechanisms are actuated, causing the staircase to pivot about the vehicle doorsill and into the vehicle vestibule to rest upon the top of the vestibule oor to form a platform step.

3. A staircase for a railway vehicle that converts from a platform-step position above the vestibule floor inside the vehicle doorsill to stair-forming position leading to a station platform which comprises:

a pair of stair treads separated by a lower riser and operatively connected thereto, said treads comprising a lower tread and an upper tread;

a connecting arm member pivotally connecting said lower and said upper treads at each end thereof and parallel to said lower riser and spaced therefrom, said connecting arm member and said lower riser being free to pivot under said upper tread from a position coplanar therewith to a position parallel to but beneath in open position and carrying said lower tread attached thereto;

an upper riser pivotally connected to said upper tread and pivotally connected to the frame of the vehicle doorsill;

a rst side frame xedly attached to said upper tread and said upper riser at each end thereof;

a second side frame fixedly attached to said lower tread at each end thereof;

an arm and link mechanism pivotally connected to each of said first side frames;

and power means for actuating said arm and link mechanisms, so that when said power means is energized said arm and link mechanisms are actuated, causing the staircase to pivot about the vehicle doorsill and into the vehicle vestibule to fold into a platform step coming to rest above the vestibule tloor.

4. The apparatus of claim 3 wherein:

said second side Iframe has a supporting stop member xedly attached thereto, said stop member acting as a support for the platform step and coming to rest on the vestibule floor when the staircase is converted and folded into the platform-step position.

5. A convertible staircase for a railway vehicle that pivots about the vehicles doorsill to fold from a stairforming position external to the vehicle into a platformstep position inside the vehicles vestibule and above the vestibule oor which comprises:

a bottom tread pivotally attached to the bottom side of a lower riser thereabove;

an upper tread;

a first side frame xedly attached to said upper tread at each end thereof and having an ear extending slightly below said upper tread;

an upper riser xedly attached to the rear of said upper tread and positioned between said first side frames and extending slightly below said upper tread, said lower riser having its upper side pivotally connected to the lower edge of said upper riser;

a second side frame xedly attached to said lower tread at each end thereof;

a connecting arm member pivotally connected to said ear of said rst side frame and having its other end pivotally connected to the lower front edge of said second side frame, said connecting arm member and said lower riser being free to pivot under said upper tread from a position coplanar therewith to a position parallel to but beneath in open position and carrying said lower tread attached thereto;

a pivoting linkage assembly operatively connected to said rst side frame at each end thereof;

and power means for actuating said linkage assembly so that when said power means is energized said linkage assembly is actuated, causing the staircase to pivot about the vehicle doorsill and into the vehicle vestibule to rest upon the top of the vestibule iloor to form a platform step.

6. The apparatus of claim 5 wherein said pivoting linkage assembly comprises:

References Cited UNITED STATES PATENTS 11/1910 Lomax 10S-447 11/ 1921 Reeder 10S-431 4/1931 Paul 105--431 8/1951 Brelsford 52-183 9/ 1960 Candlin 10S-447 FRANK L. ABBOTT, Primary Examiner.

P. C. FAW, JR., Assistant Examiner. 

